A hybrid method for optimal synthesis of multicomponent distillation processes

An optimal synthesis for distillation processes which include non-ideal multicomponent mixtures is analyzed. A detailed, mixed integer non-linear model (MINLP) is proposed for sequences of distillation, plus a hybrid method which generates an initial superstructure based on the reversible Distillation Sequence Model (RDSM). The RDSM generates the structure and provides the operational conditions for a group of columns which generate the separation scheme. By using appropriate objective functions and constraints, the RDSM can be globally solved. The number of stages in each column allow operating the columns close to the minimum reflux conditions. Both reboil and reflux are provided by means of mass coupling between adjacent columns. Results indicate that the solutions obtained and the numerical behavior are satisfactory, which allows determination of economically optimal alternatives.